It is increasingly common for users having computers interconnected by an institutional intranet or local area network to gain access to various remote sites (such as those on the "World-Wide Web") via the well-known Internet communications network. Using resident web browser applications executing on the computers, these "clients" may navigate among data ("pages") stored on various servers ("web sites") and may further view the contents of these pages as desired. In a basic network communication arrangement, clients are free to access any remote web site for which uniform resource locator (URL) addresses are available.
It is also increasingly common in network applications to provide each client with a so-called proxy server that links to the Internet. A proxy server accesses frequently requested data from the web sites and stores it locally to effectively speed-up access and reduce the download time of future requests for the data. In response to a request from a browser executing on a client, the proxy server attempts to fulfill that request from its local storage; if it cannot, the proxy server forwards the request over the Internet to a server that can satisfy the request. The server then responds by transferring a stream of data to the proxy server, which stores and forwards the data onto the client.
Each proxy server may be configured by a network administrator to provide certain functions or services to clients coupled to the network. Some of these services may be available to the general "public" of clients and others may require access rights on behalf of the clients. For example, one proxy server may be configured to offer bookmark and remote control services, whereas another proxy server may provide annotation and lesson services. The remote control and lesson services may not be available to the general public, but are only available to clients that have access rights to those specific services. Each client coupled to a proxy server may utilize the generally-available services provided by that server but only those clients that are authenticated to the network as having access rights may exploit the specifically-available services.
For an administrator desiring to offer various services to a client, the arrangement described above may be awkward and cumbersome to implement. The present invention is directed to a technique for efficiently limiting or increasing the services available to a client by way of proxy servers.